Rubber coated plywood for road material



May 7 1940- c. u. c.;mAh/IELSPACHER` 2,199,700

RUBBER COATED PLYWOOD FGR ROAD MATERIAL l Filed Aug. 16, 1.938

. INVENTOR I CLARENCE U, GRA'MELSPAGHER BYp'v e v ATTORNEYS Patented May 7, 1940 Clarence U. Gramelspacher, Jasper, Ind. Applicaties August 1e. 193s, serial No. 225,131

5 Claims.

My invention relates to covers for highways. It is the object of my invention to provide a plywood covering for highways` coated with v-ulcanized rubber to prevent skidding of automobiles:

I have found that wet rubber, such as a wet rubber tire, engaginga wet rubber surface will not skid. There is a high frictional resistance between the two rubber surfaces, even though they are wet. This is not true of a wet'concrete, brick or asphalt surface engaged by a rubber tire.

It is therefore the object of my invention to provide a strong resilient base, preferably in sections, of plywood, which can vbe firmly anchored to the underlying road base of concrete and the like, and to provide this laminated veneer body with a coating of protecting rubber, preferably corrugated, on its surface.

It is a further object to provide vulcanized strips of sponge rubber on the edges so as to permit of the necessary expansion and contraction.

I have found that laminated wood is tough, resilient and has a long life. It is particularly desirable to arrange' the sections of laminated wood with the grain transverse to the direction of travel of vehicles on the road.

It is also desirable to have the corrugations of the rubber running parallel with the grain so that these corrugations are either transverse or diagonal to the line ,of travel on the road.

It is my object to provide such road coverings particularly at road intersections, highway crossings and at such points where trame must stop, vbecause of the high coefcient of friction that this road covering provides for the stopping of automotive vehicles.

Referring to the drawing:

Figure 1 is a vertical section taken transversely through adjacent strips. A

Figure 2 is a section on the line 2-2 looking in the direction of thearrows on Figure 1.

Figure 3 is a diagrammatic view of a highway partly covered, on curves and intersections, with the road covering of this invention.

Referring to the drawing in detail, I is the earth surface upon which a concrete or other road supporting layer is placed. This layer is designated 2. Mounted. upon and anchored within the concrete layer 2 are the sections of rubber covered plywood generally designated 3. These sections are composed of a pluralityr of layers of wood veneer 4, joined together by adhesive 5.

After they are so assembled with the grain of the wood preferably running lengthwise of the oblong sections, the body of wood is wrapped with a rubber covering 6. ,The-top of this rubber covering 'l is corrugated: The side walls are provided with layers of rubber@ of such composi-- tion that it will sponge when vulcanized.

There has already been assembled in the wood veneer layers attaching bodies 9 having enlarged heads Ill extending beyond Ythe body of the as,-` sembly. The'complete section is then placed in a vulcanizing press and vulcanized. It is now ready for assembling.'

Holes il are formed in the concrete base 2. The enlarged heads lll are inserted in the holes, which holes are preferably filled with a plastic material such as concrete or molten lead i2, so that when the material i2 hardens, the section will be firmly attached to the base 2.

The bodies 9 are provided with nuts to so that in the event the upper rubber surface i wears away, then the nuts 9a may be-removed and the sections of wood in the remaining rubber liftw from the bodies 9. The wood sections can then be recovered with rubber, revulcanized and replaced.

Any holes left in the rubber for receiving the nuts sa, when the sections are so replaced, can

be lled with rubber and vulcanized in position. G It will be understood that the plywood sections are capable of withstanding a high temperature in a vulcanizing press to have the rubber vulcanized thereto. 'Ihe rubber protects the wood veneer from water, freezing and dirt.

It will be further understood that the method of attaching is optional. I comprehend within my invention making the edges of these sections interlocking, either 'with or withoutthe sponge rubber llers on the margins thereof.

As will be observed in Figure 3,-I arrange at maximum dimension each of the blocksv 3 transversely of the road. 'I'his places the corrugations 'i transversely of theroad.

A great variety of dierent ways of attaching these blocks may be employed, depending upon' the nature of the underlying base 2, whether it is desired to recover the wood sections, et cetera;

It will be understood that yI desire to comrelatively thin layers of wood veneer adhesively 55 d5 prehend within my invention such modiications. las may be necessary to adapt it to varying con-- an integral vulcanized rubber covering complete- 1y enclosing said plywood block` on all surfaces thereof. Y

2. A new article of manufacture adapted to be used as a road surfacing comprising a plywood block made up of a. plurality of superimposedrelatively thin layers of wood veneer adhesively laminated to one another with the layers horizontally disposed parallel to the road surface, an-

integral vulcanized rubber covering completely *enclosing said plywood lzfloclrl on all surfaces A thereof, and layers of vulcanized sponge rubber surrounding the side walls of said rubber covered block and integral with said rubber covering.

3. In combination, in a highway, a supporting concrete base and a plurality of paving blocks mounted thereon, each of said blocks comprising a plywood block made up of a plurality of superimposed relatively thin layers of wood veneeradhesively laminated to one' another with the layers horizontally disposed parallelto the road surface, and an integral vulcanized rubber covering completely enclosing said plywood block on all surfaces thereof, said blocks being mounted with the grain of the wood of said plywood transverse to the line of trafiic.

4. In combination, in a highway, a supporting base and a plurality of paving blocks mounted thereon, each of said blocks comprising a plywood block made up of a plurality of superimposed relatively thin layers of wood veneer adhesively laminated to one another with the layers horizontally disposed parallel to the road surface, an integral vulcanized rubber covering completely Aenclosing said plywood block onv all surfaces thereof and layers of vulcanized sponge rubber surrounding the side walls of said rubber covered block and integral with said rubber covering, said blocks being mounted with the sponge rubber side walls of adjacent blocks contacting one another, said sponge rubber allowing for expension and contraction between adjacent blocks.

5. In combination, in a highway, a supporting base and a plurality of paving blocks mounted thereon, each of said blocks comprising a plywood block made up of a plurality of superimposed relatively thin layers of wood veneer adhesively laminated to one another with the layers horizontally disposed parallel to the road surface, an integral vulcanized rubber covering completely enclosing said plywood block on all surfaces thereof, and vertical attaching means secured into said blocks and extending through at least a portion of said lamination downwardly into and secured into said base, said attaching means being provided with means preventing upward movement of said blocks.

CLARENCE U. GRAMELSPACHER. 

